Malignant mesothelioma with squamous differentiation

Abstract

To the best of our knowledge, this is the first case report of mesothelioma with extensive squamous differentiation in the English-language literature. The extensive squamous differentiation reminiscent of squamous cell carcinoma can be a pitfall in the pathological diagnosis of pleural cytology and that of biopsy specimens from patients with mesothelioma. Here, we report autopsy findings of a case of malignant mesothelioma with portions of extensive squamous differentiation, mimicking a squamous cell carcinoma.

SMARCB‐1 deficient squamous cell carcinoma of a mediastinal cyst

“…However, diffuse expression of BAP1, and negative expression of calretinin, WT1, D2‐40 and GATA3 did not suggest the diagnosis of mesothelioma. Also, the tumor in this case was none of the above both morphologically and immunohistochemically . So the mechanism of carcinogenesis was somewhat unclear, and we suspected the tumor arose in the wall of the cyst, not in the lining mesothelium.…”

“…Pleura-based tumor spread was indeed reminiscent of mesothelioma, and malignant pleural mesothelioma with squamous differentiation was reported recently. 9 However, diffuse expression of BAP1, and negative expression of calretinin, WT1, D2-40 and GATA3 did not suggest the diagnosis of mesothelioma. Also, the tumor in this case was none of the above both morphologically and immunohistochemically.…”

“…Other tumors of the pericardium include several kinds of sarcomas, germ cell tumor or lymphoma. Pleura‐based tumor spread was indeed reminiscent of mesothelioma, and malignant pleural mesothelioma with squamous differentiation was reported recently . However, diffuse expression of BAP1, and negative expression of calretinin, WT1, D2‐40 and GATA3 did not suggest the diagnosis of mesothelioma.…”

“…Also, the tumor in this case was none of the above both morphologically and immunohistochemically. 4,9,10,11 So the mechanism of carcinogenesis was somewhat unclear, and we suspected the tumor arose in the wall of the cyst, not in the lining mesothelium.…”

Rare case of squamous cell carcinoma arising from tunica vaginalis in a background of chronic hydrocele

“…Furthermore, the above described focal gain of expression for Ber-Ep4 and p63 in the hydrocele is also supportive of a metaplastic process in a setting of long standing chronic inflammation. Interestingly, SCC transformation (or divergent differentiation) of mesothelioma was recently documented in a thoracic mesothelioma in which there was complete loss of mesothelial markers in the SCC component 5 …”